Not Applicable
Not Applicable
(1) Field of the Invention
The present invention relates to a rotary device which is used for rotating a suspended load. In particular, the present invention relates to a rotary device which has a boom which connects to a material handler vehicle for rotating a load lifted by the material handler vehicle.
(2) Description of the Related Art
The ability to lift and rotate suspended loads with precision control greatly enhances any lifting operation. To rotate a suspended load safely, the rotating force must be controlled. Controlling the rotating force eliminates the possibility of applying unforeseen twisting forces to the rigging (chokers, slings, etc.). Controlling the rotating force also reduces the amount of damage or harm produced should the rotating load which is being lifted come in contact with a fixed object or structure.
In the past, to rotate a suspended load such as during steel erection, a tag line and tag line person were used. This process involved controlling a suspended load by tying a rope to one (1) end of the load being lifted. However, attempting to control a suspended load from the ground can have numerous safety hazards. In addition, in some cases where the load is lifted high, obstructions to the tag line or the tag line person make the use of a tag line impossible. In this case, the operator must bump the load against some existing structure or object to try to get the load correctly positioned once the load is hoisted.
The related art has shown various types of load rotating devices which allow for slippage should the load encounter an obstacle. Illustrative are U.S. Pat. No. 2,823,944 to Anderson et al; U.S. Pat. No. 3,037,804 to Kraeling et al; U.S. Pat. No. 3,046,046 to Gris; U.S. Pat. No. 3,210,115 to Graham et al and U.S. Pat. No. 3,633,961 to Speransky.
Anderson et al describes a motorized swivel hook device. The swivel hook of the device has a vertical shank which is connected to a thrust collar extending between a flange at the bottom of the shank and the underside of a roller bearing. An annular flange of the thrust collar overlies the hub of a driven gear. The driven gear connects with a drive gear positioned on an output shaft of a speed reducer. The upper and lower faces of the flange of the collar are sandwiched between the driven gear and a plate. Friction material is interposed between the flange and the driven gear and the flange and the plate. By tightening nuts on bolts extending through the driven gear, flange and plate, a predetermined amount of frictional force is provided between the driven gear and plate on one hand and the thrust collar on the other hand. Thus, when the rotating hook encounters a resisting force exceeding the frictional force exerted on the flange, the gears will be able to rotate, with the driven gear and the plate frictionally slipping relative to the flange.
Kraeling et al describes a rotary hook for a traveling block for cranes. The crane hook block is comprised of the sheaves and the hook swivel which are secured to each other by means of parallel links. The rotary drive for rotating the hook relative to the block is provided with a friction clutch to prevent destruction of the gear drive if the hook is accidentally struck against an object and caused to twist which will cause the clutch to slip rather than destroy the apparatus. Thus slippages occur between the hook nut which is connected to the spindle of the hook clevis and the ring gear which is rotated by the pinion on the end of the output shaft of the gear reducer. Springs are used to provide sufficient compression to provide a friction drive between the upper and lower faces of the ring gear and the friction clutch linings. One (1) friction clutch lining is located between the lower face of the ring gear and the shoulder of the hook nut. The other friction clutch lining is located between the upper face of the ring gear and the pressure rings which hold the springs.
Gris describes a motor activated rotary crane hook. In each embodiment the hook is connected to the upper member by a swivel connection which allows for manual rotation of the load when necessary. The object of this invention is to provide a power means for rotating the hook in relation to its upper member. In each embodiment, the motor acts to rotate the hook directly. The hook does not rotate with the shaft.
Graham et al describes a power rotatable hook device which includes a torque limiting means such that if the load meets an obstruction, the torque limiting device would slip which would enable the motor to continue running. When the obstruction is removed, the load resumes rotation. The torque limiting means is of the slip type and can be of the eddy current type. The torque limiting device is selected so that it will slip at a torque value less than that which the speed reducer can safely handle.
Speransky describes a crane hook rotated by power for proper load orientation. The invention includes a hollow shaft which is connected to a shank extension of the shank of the hook. An electric motor rotates the hollow shaft and the hook. A plunger is slidably mounted in the shaft and an insert is disposed between the upper end of the shank extension and the lower end of the plunger. The upper end of the insert has a keyway within which is disposed a radial key carried by the lower end of the plunger. This key has tapered sidewalls so that the key will ride out of the keyway should the hook encounter turning resistance.
Also of interest are U.S. Pat. No. 3,009,728 to Breslav and U.S. Pat. No. 5,125,707 to Chaen et al.
Breslav describes a rotatable load supporting or lifting device. The speed reduction device used in rotating the hook includes a worm gear and worm shaft. A friction clutch is located on the worm shaft to drive the worm under ordinary conditions. The clutch allows slippage between the motor and the worm when the worm meets an obstruction.
Chaen et al describes a rotary load lifting device which allows for remotely operating the driving device provided on a hook block which is connected to a load lifting hook. The driving device and hook block each have chain wheels which are connected together by a chain.
There remains the need for a rotary device which includes a telescoping boom for mounting on a material handler vehicle and which uses the weight of the load to produce friction between the driven shaft and the load to rotate the load while controlling the amount of friction so that if the load should encounter an obstacle during rotation, the frictional force will be overcome and the load will stop rotating.
The present invention relates to a unit having a boom and a load rotary device which is used to rotate a suspended load in a controlled manner. In one (1) embodiment, the unit includes a boom with a hydraulically powered, suspended load rotary device. The rotary device includes a first bracket fixably mounted to the boom. A second bracket is movably mounted to the first bracket. The first and second brackets each have V-shaped or triangular shaped openings. The brackets are connected together by a U-shaped, cylindrical connector which extends through each of the openings. The shape of the openings and the shape of the connector allows the second bracket to swing freely with respect to the first bracket. A motor bracket is mounted to the second bracket by a spacer. The spacer and motor bracket are mounted on a side opposite of the first bracket. The motor is mounted on the motor bracket such that the motor shaft extends downward through the motor bracket. The drive gear is mounted on the end of the motor shaft. A driven shaft extends from the second bracket through the spacer and motor bracket and through a third bracket rotatably mounted on the second end of the driven shaft. A driven gear is fixably mounted on the driven shaft between the motor bracket and the third bracket. The motor is positioned such that the teeth of the drive gear engage the teeth of the driven gear. The driven shaft extends through a hole in the third bracket. The third bracket is secured to the drive shaft by a nut. A friction plate is spaced between the third bracket and the nut. When a load is connected to the third bracket and the load is lifted, the weight of the load pulls the third bracket downward into frictional contact with the friction plate. To rotate the load, the motor is activated which rotates the drive gear which rotates the driven gear and drive shaft. The frictional contact between the third bracket and the friction plate causes the rotating drive shaft to rotate the third bracket and the load. The unit is used to provide a xe2x80x9csafe and efficientxe2x80x9d means to unload and erect steel structural framing members (columns, beams, trusses, etc.). The unit of the present invention will allow the operator of the material handler vehicle to lift and rotate a load of any size or weight by simply operating a hydraulic control lever.
In the present invention, the weight of the load itself produces the friction that controls the force to rotate the load. Regardless of the size or weight of the load, only a minimal force, sufficient to rotate the load, is needed to be applied to rotate the load. In addition, if the rotating load comes in contact with an obstacle, or if a person holds onto the load while the load is rotating, the operator loses his ability to rotate the load and the load stops rotating and the rotary device simply slips. Once the load is clear of the obstacle or the person releases the load, the operator regains control of the rotation of the load and only the minimal force is required to rotate the load.
One (1) feature of the present invention is the ability to rotate any suspended load, regardless of the weight of the load, with only minimal force. The weight of the load on the driven shaft on the top side of the friction plate and the bottom side of the first portion of the third bracket, provides the friction between the surfaces required to allow only minimal force to rotate the load. The friction caused between the friction plate and the first portion of the third bracket, allows the operator to rotate the load with minimal rotational force. The amount of steel-to-steel friction or frictional resistance (force) between the friction plate and the first portion of the third bracket is controlled by the weight of the load. The operator has unrestricted, precise control of the rotation of the driven shaft and of the friction plate while having only the weight controlled frictional force to rotate the third bracket and the load. Due to the frictional forces between the friction plate and the third bracket, the operator has precise control over the rotation of an unobstructed load by rotating the driven shaft. However, when the load comes in contact with an obstacle, the operator""s control over rotation of the load becomes restricted. The use of a weight controlled frictional surface to rotate the load allows a person to hold or rotate the load in one (1) direction, while the operator is applying a force to rotate the load in the opposite direction.
The structural design of the boom and rotary unit make this unit extremely rugged and maintenance free. The simple construction of the unit makes it convenient and efficient and practical to use.
The present invention relates to a rotating device for rotating a load, which comprises: a first bracket having an opening; a second bracket having a first opening and a second opening; a first connector connected between the opening in the first bracket and the first opening in the second bracket to connect the first bracket to the second bracket; a driven shaft having a first end and a second end with the first end rotatably extending through the second opening in the second bracket; a driven gear fixably mounted on the driven shaft; a motor mounted on the second bracket; a motor shaft having opposed first and second ends and connected at the first end to the motor; a drive gear mounted at the second end of the motor shaft and positioned such that the drive gear engages the driven gear; a third bracket having an opening wherein the second end of the driven shaft rotatably extends through the opening to rotatably mount the third bracket to the driven shaft; and a second connector mounted on the third bracket configured to connect the load to the third bracket wherein, in use, with the load connected to the third bracket, the motor is activated to rotate the drive gear which rotates the driven gear and the driven shaft, as the driven shaft rotates, a weight of the load on the third bracket causes friction between the second end of the driven shaft and the third bracket which causes the driven shaft to rotate the third bracket and the load.
Further, the present invention relates to a rotating device for rotating a load, which comprises: a first bracket having an opening; a second bracket having a first portion perpendicular to a second portion with an opening in the first portion spaced apart from the second portion and a notch in the first portion adjacent an opening in the second portion; a first connector extending between and connected to the opening in the first bracket and the opening in the first portion of the second bracket to connect the first bracket to the second bracket; a driven shaft having a first end and a second end with the first end rotatably extending through the opening in the second portion of the second bracket and into the notch in the first portion of the second bracket; a driven gear fixably mounted on the driven shaft; a motor mounted on the second bracket; a motor shaft having opposed first and second ends and mounted at the first end to the motor; a drive gear mounted on the second end of the motor shaft and positioned such that the drive gear engages the driven gear; a third bracket having an opening wherein the second end of the driven shaft rotatably extends through the opening; and a second connector mounted on the third bracket configured to connect the load to the third bracket wherein, in use, with the load connected to the third bracket, when the motor is activated, the drive gear rotates the driven gear and the driven shaft, as the driven shaft rotates, a weight of the load on the third bracket causes friction between the second end of the driven shaft and the third bracket which causes the driven shaft to rotate the third bracket and the load.
Still further, the present invention relates to a load rotating device for use with a material handler vehicle having a boom to rotate a load, which comprises: a first bracket configured to be mounted on the boom of the material handler vehicle and having a triangular shaped opening; a second bracket having a first plate with a triangular shaped opening and a second plate mounted perpendicular to the first plate with a hole along a longitudinal axis of the device; a first connector extending between the triangular shaped openings of the first and second brackets to connect the first and second brackets; a motor bracket mounted to the second plate of the second bracket on a side opposite the first plate and having a hole aligned with the hole in the second plate of the second bracket, the motor bracket having a pair of opposed arms which extend outward perpendicular to the longitudinal axis of the device; a motor mounted on one of the arms of the motor bracket; a motor shaft having opposed first and second ends and connected at the first end to the motor and extending toward the second end parallel to the longitudinal axis of the device in a direction away from the first bracket; a drive gear mounted at the second end of the motor shaft opposite the motor; a driven shaft having opposed first and second ends with the first end positioned through the hole in the second plate of the second bracket and the hole in the motor bracket such as to extend along the longitudinal axis of the device; a driven gear fixably mounted on the driven shaft adjacent the drive gear such that the drive gear mounted on the motor shaft of the motor engages the driven gear to rotate the driven gear and driven shaft; a third bracket having a hole with the second end of the driven shaft rotatably mounted through the hole; a second connector mounted on the third bracket configured to connect the load to the third bracket; and a friction plate mounted on the second end of the driven shaft adjacent a side of the third bracket opposite the second bracket wherein, in use, when the load is secured to the third bracket and the motor is activated to rotate the driven shaft, a weight of the load on the third bracket causes friction between the third bracket and the friction plate which causes the driven shaft to rotate the third bracket and the load and wherein a force of friction between the third bracket and the friction plate is such that application of a force in a direction opposite to a direction of rotation of the driven shaft overcomes the force of friction between the third bracket and the friction plate such as to stop rotation of the load.
Further still, the present invention relates to a rotating unit for use with a lift vehicle for rotating a load, which comprises: a boom having a first end and a second end; a mounting bracket mounted on the first end of the boom configured to removably attach the rotating unit to the lift vehicle; a first bracket having an opening and mounted on the second end of the boom; a second bracket having a first portion perpendicular to a second portion with an opening in the first portion spaced apart from the second portion and a notch in the first portion adjacent an opening in the second portion; a first connector extending between and connected to the opening in the first bracket and the opening in the first portion of the second bracket to connect the first bracket and the second bracket together; a driven shaft having a first end and a second end with the first end rotatably extending through the opening in the second portion of the second bracket and into the notch in the first portion of the second bracket; a driven gear fixably mounted on the driven shaft; a motor connected to the second bracket; a motor shaft having opposed first and second ends and connect at the first end to the motor; a drive gear mounted on the second end of the motor shaft and positioned such that the drive gear engages the driven gear; a third bracket having an opening wherein the second end of the driven shaft rotatably extends through the opening; and a second connector mounted on the third bracket configured to connect the load to the third bracket wherein, in use, with the load connected to the third bracket and the motor activated, the motor rotates the motor shaft and drive gear which rotates the driven gear and the driven shaft, as the driven shaft rotates, a weight of the load on the third bracket causes friction between the second end of the driven shaft and the third bracket which causes the driven shaft to rotate the third bracket and the load.
Further, the present invention relates to a rotating unit for use with a lift vehicle for rotating a load, which comprises: a boom having a first end and a second end; a mounting bracket mounted on the first end of the boom and configured to removably attach the rotating unit to the lift vehicle; a first bracket mounted on the second end of the boom and having a triangular shaped opening; a second bracket having a first portion perpendicular to a second portion with an opening in the first portion spaced apart from the second portion, the opening having a triangular shape and a notch in the first portion adjacent an opening in the second portion; a first connector extending between and connected to the opening in the first bracket and the opening in the first portion of the second bracket; a driven shaft having a first end and a second end with the first end rotatably extending through the opening in the second portion of the second bracket and into the notch in the first portion of the second bracket; a driven gear fixably mounted on the driven shaft; a motor connected to the second bracket; a motor shaft having a first and second end and mounted at the first end to the motor; a drive gear mounted on the second end of the motor shaft and positioned such that the drive gear engages the driven gear; a third bracket having an opening wherein the second end of the driven shaft rotatably extends through the opening; a friction plate mounted on the second end of the driven shaft adjacent a side of the third bracket opposite the second bracket; and a second connector mounted on the third bracket and configured to connect the load to the third bracket wherein, in use, with the load connected to the third bracket and the motor activated, the motor rotates the drive gear which rotates the drive gear and the driven shaft, as the driven shaft rotates, a weight of the load on the third bracket causes friction between the friction plate and the third bracket which causes the driven shaft to rotate the third bracket and the load.
Finally, the present invention relates to a method for rotating a load which has been lifted using a material handler vehicle, which comprises the steps of: providing a rotary device configured to be attached to the material handler vehicle and including a first bracket having an opening and configured to be mounted on the material handler vehicle; a second bracket having a first portion perpendicular to a second portion with an opening in the first portion spaced apart from the second portion and a notch in the first portion adjacent an opening in the second portion; a first connector extending between and connected to the opening in the first bracket and the opening in the first portion of the second bracket to connect the first and second bracket together; a driven shaft having a first end and a second end with the first end rotatably extending through the opening in the second portion of the second bracket and into the notch in the first portion of the second bracket; a driven gear fixably mounted on the driven shaft; a motor having a motor shaft and a drive gear and positioned such that the drive gear engages the driven gear; a third bracket having an opening wherein the second end of the driven shaft rotatably extends through the opening; and a second connector mounted on the third bracket and configured to connect the load to the third bracket; attaching the rotary device to the material handler vehicle; attaching the load to the third bracket of the rotary device using the second connector; and activating the motor which rotates the motor shaft, the drive gear, the driven gear and the driven shaft wherein a weight of the load on the third bracket causes friction between the second end of the driven shaft and the third bracket such that the third bracket with the load rotates with the driven shaft.
The substance and advantages of the present invention will become increasingly apparent by reference to the following drawings and the description.